Nombre en español: Curruca Collareja

Nombre en inglés: Collared Gnatwren

Nombre científico: Microbates collaris

Familia: Polioptilidae

El soterillo acollarado (Microbates collaris)​ también denominado saltón acollarado, chirito acollarado, curruca collareja,​ es una especie de ave paseriforme de la familia Polioptilidae que vive en Sudamérica.

Similar a un Cucarachero pero con pico y cola larga. Se le encuentra en tiarras bajas al oriente de los Andes. Su nombre Microbates significa pequeño caminante yderiva de las raíces griegas mikros = pequeño y bates = caminante. Por otra parte, su epíteto específico collaris viene del latín collare que significa collar y hace alusión a su collar negro característico.

Distribución y hábitat

Se encuentra en Brasil, Colombia, Ecuador, la Guayana francesa, Guyana, Perú, Surinam y Venezuela.

Su hábitat natural es el sotobosque de la tierra firme en las selvas húmedas tropicales de regiones bajas de la Amazonia, hasta los 900 m de altitud.

En colombia se encuentra por debajo de 500 m de altura sobre el nivel del mar al oriente de los Andes desde el occidente de Putumayo hasta Vaupés pasando por Caquetá y hacia el sur hasta Amazonas. Es posible que también se encuentra al oriente de Guainía.

Descripción

Mide 10,5​ a 11 cm​ de longitud. Presenta líneas superciliares blancas y la cara cruzada por una línea postocular negra; mejillas blancas bordeadas por una mancha malar negra. La corona, la nuca, el dorso y la cara superior de las alas y la cola son de color castaño. Las partes inferiores son blancas con una mancha negra en el pecho en forma de media luna o collar.

Especies Similares

Se diferencia fácilmente por características como la banda pectoral negra, patrón estriado en la cabeza y su pico largo. Podría confundirse con el Hormiguerito Bandeado (Dichrozona cincta)pero este tiene la rabadilla negra cruzada por una banda blanca, hombrops punteados de blanco, barras alares ante y collar negro de puntos, no continuo. La Curruca Rabicunda (Microbates cinereiventris) tiene rostro café rufo y collar de estrías negras interrumpido.

Diferencias Regionales

Se reconocen 5 subespecies: M. c. torquatus, M. c. paraguensis,  M. c collaris, M. c. colombianus y M. c. perlatus, de las cuales las tres últimas se encuentran en Colombia y se diferencian por la coloración de las partes altas, color de los flancos, ancho de la banda pectoral y marcas faciales.

Alimentación

Se alimenta de insecto, que busca en el nivel bajo del bosque, a veces en bandas mixtas con otras especies y ocasionalmente persiguiendo las presas ahuyentadas por hormigas guerreras.

Reproducción

Construye el nido con hojas secas, en forma de taza, cerca del suelo. La hembra pone 2 huevos blancos con puntos oscuros.

Collared gnatwren

The collared gnatwren (Microbates collaris) is a species of bird in the family Polioptilidae. It is found in Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela. Its natural habitat is subtropical or tropical moist lowland forests.

The Collared Gnatwren is restricted to northern Amazonia, where it is a widely distributed but generally rather uncommon resident, from southern Venezuela and the Guianas to the north bank of the Amazon, and west to northeast Peru. If seen well, this is a distinctive bird, characterized by its proportionately very long bill, long white supercilium, black eyestripe, malar stripe and pectoral band, with otherwise earth brown upperparts, and white underparts. As many as five subspecies have been recognized, which differ chiefly in the degree and extent of any rufous tones above. The Collared Gnatwren is perhaps most easily located by voice; the song is a series of softly uttered peeee notes, but the harsh jipp given in alarm, or as a scold, is perhaps more likely to draw an observer’s attention. The species moves very rapidly through the lower growth of tropical forest, often with two or three conspecifics, searching all the while for arthropods, and the Collared Gnatwren sometimes also joins mixed-species foraging flocks. Only one nest has ever been found and described.

Identification

11 cm; 10–12 g. Has long (18–20 mm), slender bill and stubby, cocked tail. Nominate race brown above, with slightly darker crown and greyish side of head; head boldly marked, with white cheek, ear-coverts, super­cilium and lores, thick black postocular and malar stripes; wings dull black to olive-brown, with rufescent tinge on outer edges of secondaries; creamy white below, with wide black ­pectoral band, olive-brown flanks and undertail-coverts; iris dark brown; upper mandible dark brownish-horn, lower mandible pale horn to yellowish; legs grey. Sexes similar. Juvenile lacks pectoral band, white supercilium and black facial markings. Races vary in upperpart coloration, flank colour, width of pectoral band, and facial markings: paraguensis is more rufescent than nominate overall, especially on crown and flanks; perlatus has upperparts darker and duller, black facial marks thicker (reduced white on face), thicker pectoral band, greyer flanks; colombianus has grey sides, rich brown crown contrasting heavily with mantle, mantle duller than nominate but brighter than previous, facial pattern intermediate between those two; torquatus is dull brown with less rufous tone above, has facial markings similar to last, flanks olivaceous brown, pectoral band broader than nominate.

Habitat

Undergrowth of wet, humid terra firme forest; primary rainforest in French Guiana and Suriname, but not in secondary or riparian forests; rarely occurs at forest edges. Usually found near water. Primary ecoregions occupied by each race include several types of moist forest: Negro-Branco(nominate race); Guyanan Highlands (paraguensis); Solimões-Japurá (perlatus); Napo (colombianus); and Guianan (torquatus). Mostly below 500 m.

Movement

Resident.

Diet and Foraging

Small arthropods. Moves actively through lower vines and tangles of dark undergrowth, usually at or less than 25 cm from ground; stretches neck to pick small insects and spiders from foliage, and probes in ground litter and curled dead leaves. Often in mixed flocks of understorey insectivorous birds; may attend ant swarms.

Sounds and Vocal Behavior

Harsh scolding notes, most commonly a nasal, complaining “nyeeeh” or “nyaaah”, sometimes repeated, similar to scolds of M. cinereiventris. Song a series of soft, thin notes, “peeee” or “eeeeea”, steadily repeated at c. 4-second intervals for long periods; contact notes described from Suriname as continuous, high chirping, may possibly refer to same vocalization. Also, a harsh scolding “jipp” and a loud, chattering alarm call, resembling scolds of M. cinereiventris. Not particularly vocal, especially for a forest-interior species.

Breeding

Little known. One nest found in mid-May in Brazil; fledglings observed Aug–Oct in Guyana. Usually seen in pairs or trios, suggesting that pair-bond maintained throughout year. One nest described, a bulky, leafy cup, walls composed of compacted rotten leaves and leaf rachises, lining of thinner soft brown material, external diameter and height each 10 cm, internal cup 5 cm in diameter and 4 cm deep; well concealed c. 0·4 m from ground, supported by crossing twigs and dead thorny palmetto, in general appearance resembling “a pile of debris”. Clutch 2 eggs, white, a few small brown spots forming wreath around large end; incubation period at least 14 days; nestling period 12–13 days.

Conservation Status

Not globally threatened. Widely distributed; generally scarce, although easily overlooked owing to inconspicuous behaviour. Uncommon to local in Venezuela; scarce but widely distributed in Suriname; uncommon in Amazonas, in Brazil; common in Vaupés, in Colombia; rare and local in Ecuador. None of the races is restricted to ecoregions considered to be under serious threat according to current and projected conservation status.

Fuentes: Wikipedia/eBird7xeno-canto/WikiAves/Birds of the world